<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="https://fhir.nhs.uk/StructureDefinition/Extension-NHSEngland-GestationPeriodObservation" />
  <name value="GestationPeriodObservation" />
  <status value="draft" />
  <date value="2022-09-14T14:21:48.4837633+00:00" />
  <fhirVersion value="4.0.1" />
  <kind value="complex-type" />
  <abstract value="false" />
  <context>
    <type value="element" />
    <expression value="Patient" />
  </context>
  <type value="Extension" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  <derivation value="constraint" />
  <differential>
    <element id="Extension.url">
      <path value="Extension.url" />
      <fixedUri value="https://fhir.nhs.uk/StructureDefinition/Extension-NHSEngland-GestationPeriodObservation" />
    </element>
    <element id="Extension.value[x]">
      <path value="Extension.value[x]" />
      <type>
        <code value="Reference" />
        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Observation" />
        <aggregation value="referenced" />
      </type>
    </element>
  </differential>
</StructureDefinition>